1. Field of the Invention
The present invention relates to guides for installation along the sides of a container-transporting conveyor system. More specifically, the present bendable/twistable rolling conveyor guide is adapted for installation along straight, curved and/or twisting sections of a conveyor system.
2. Description of the Related Art
Guides mounted on opposite sides of conveying systems are used in a variety of places in industrial installations. For example, they are used for combining (channeling a wide procession of conveyed articles in a disorderly array into a single file), forcing articles around bends in the conveying system, or simply preventing articles from falling off the side of the conveyor. Generally, there is at least one guide mounted on each side of the conveyor.
Guides may either be fixed or rolling, depending upon the nature of the guide surface that contacts the conveyed articles. Fixed guides provide a smooth surface for articles to contact, while rolling guides provide rotatable elements mounted upon axles. Guides of both types provide a low friction guiding surface for a large variety of individual containers including glass, metal, plastic and paperboard, and packages like cardboard boxes, and plastic wrapped bundles or trays. Excess friction in any of these applications can cause line stoppage, package jamming and possible damage, product spillage or skewed orientation.
In powered conveyor applications especially, fixed guides generally provide too much friction to be useful, especially when a container or package must be guided around a turn or through a transfer from one conveyor to another. Rolling guides are an excellent solution to these problems. In some curved sections of conveyors, there is only a rolling guide on one side of the conveyor, with a fixed guide on the other side. Where only one rolling guide is used, the rolling guide is usually mounted on the outside, or larger radius, of the curve.
Rolling guides are often constructed in a similar manner. A rolling member is positioned on a shaft or axle and contacts the product/package surface. Sizes of rolling members, and heights of rolling guides, vary. Guides can be from one inch with one member to ten inches with fifteen-plus members. Rolling members can interlock (nest) or stand adjacent. A dense interlocked pattern is generally preferred, because the interlocking members minimize gaps that tend to catch passing articles. The axles are in turn connected to a structural supporting member by means of an axle-positioning plastic cap. Aluminum extrusions, bars of steel or aluminum and formed sections of sheet metal are the most common materials for the supporting member.
For economic reasons, guides are generally manufactured in standard lengths. However, applications for guides often require unique bead lengths. Therefore, either each length must be amenable to being cut, bent and/or twisted by the purchaser to conform to each application, or the purchaser must special order the specific lengths and radii of guides needed, which is typically a more expensive option.
Examples of rolling guides are shown in U.S. Pat. Nos. 3,934,706, 4,962,843 and 5,143,200, and VALU GUIDE Model #684. Each of these guides generally comprises an upper and a lower frame member that are adapted to be mounted alongside and parallel to the conveyor. U.S. Pat. No. 4,962,843 comprises a plurality of vertically stacked frame members. A plurality of axles are disposed between the frame members, usually with the longitudinal axis of each axle oriented perpendicularly to the conveying surface. Rotatably attached to the axles are beads, which are generally spherical, or rollers, which are generally cylindrical with protruding flanges that are either round or polygonal.
This guide configuration is particularly useful for combining, where each guide is straight. However, none of these guides are easily bent after they have been assembled. Further, none of these guides is capable of being twisted. Bending or twisting these guides often results in radical deformation of the supporting structure and even failure. Therefore, none of these guides are well suited for use in curved or twisting sections of a conveying system unless they are custom manufactured to meet a particular customer's need.
Two examples of guides that are more easily bent by the purchaser are the Marbett Model # 580 and 581, and the System Plast device. Each length of these guides comprises multiple short sections of frame members that are all flexibly attached to one another by means of plastic hinges. The back side of each section contains a channel that is adapted to be slidably attached to a bent mounting strip. These designs have some major drawbacks, however. First, the minimum bending radii are rather high (approximately 13″ for an internal curve, and 15″ for an external curve for the Marbett, and approximately 18″ for an internal curve, and 24″ for an external curve for the System Plast). A plant layout requiring tighter radii would not be able to use these guides. Second, because the device only bends between sections, and each section contains four axles, it does not provide an entirely smooth curve. The transition points between sections have a tendency to catch passing articles on the conveyor, leading to jamming. Third, neither of these guides is capable of being twisted.
The design of all of the above-mentioned guides also makes them more expensive to manufacture. The axles must first be inserted into an axle-positioning member. After the rotatable elements have been installed, every single axle must be lined up properly before the other axle-positioning member can be secured to the other end of the axles. This is a very tedious process that is difficult to automate.
A guide that is easily and cheaply manufactured, easily bent and/or twisted by the purchaser, is capable of being bent to small radii, and that doesn't have a tendency to cause conveyed articles to jam would be of great benefit in any industry that uses conveyors.